Ornamental stitch attachments for sewing machines



p 30, 1958 R. E. JOHNSON 2,853,966

ORNAMENTAL STITCH ATTACHMENTS FOR SEWING MACHINES Filed Jan. 28, 1955 illlllllllllllll Hindu Fig 3 INVENTORV Ralph Johnson wmvass T \k h 11;,

A TTORNE Y United States Patent QRNA EN A TI CH- TACHMENTS FOR E NG MAQHINES- Ralph E. Johnson, Mountainside, N. J., assignor to The Singer Manufacturing Company, Elizaheth, N. J., a corporation of Newvlersey Application January 28, 1 95 5, S erjal No 484,621 6 Claims. (Cl. 112-160) This invention relates to ornamental stitch attachments of the work-jogging type for sewing machines and, more particularly, to an improved operating mechanism for a sewing machine work-jogging attachment.

It is an objectof this invention to provide an operating mechanism for a work-jogging attachment by which the motion necessary to efiect jogging of the work may be transmitted smoothly and efficintly.

Another object of this invention is to provide an operating mechanism for a work-jogging attachment in which frictional resistance between the moving parts is minimized so that binding or s eiiing of the parts is eliminated.

With the above and additionab objects and advantages in view, as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in theaccompanying. drawings of a preferred embodiment thereof: in which: i i

Fig. 1 represents a top plan view of a cam-controlled work-jogging attachment in which the cam has been removed to eXpose the actuating mechanism;

Fig. 2 represents a side elevational view of the workjogging attachment with the cam in section and portions of the frame and bight control slider broken away to expose the actuating mechanism; and i Fig. 3 is a diagrammatic top plan view of a portion of the actuating mechanism which cooperates with the pat tern cam. a

Referring to the drawings, the actuating mechanism of the present invention is embodied in a work-jogging attachment of the type disclosed in thecopending patent application of I. P. Enos, Serial No. 461,149, filedOctober 8, 1954, to which reference may be had for a detailedv description of those features ofthe attachment which are not directly concerned with the actuating mechanism of; this invention.

The work-jogging attachment comprises a frame 11 which carries a block 12 slottedpto embrace a sewing machine presser, bar 13 to which the attachment frame is secured by a thumb screw 14 in place of. the usual sewing machine presser foot.

Iournaled between spaced upstanding arms 15 -15 of the attachment frame is a stud, shaft 16 tolwhich a forked attachment actuating arm 17 is secured. As is customary in sewing machine work-jogging attachments, the forked arm isv adapted to embrace the usual: needle-clamp 18 by which a needle 19 is removably secured in the extremity of a sewing machine needle bar 20. Reciprocation of the sewing machine needle bar is thus harnessed to oscillate the attachment actuating arm 17.

A lug 21 struck out from the actuating arm 17 is operatively engaged between spaced upstanding fingers 2222 of a slide plate 23 which is constrained for reciprocation on the attachment frame by a pair of slot-and-pin connections therewith, as indicated at 24. Pivoted at 25 to the slide plate is a pawl 26 which is biased by a spring 27 into engagement with the teeth of a ratchet wheel 28 P ent d Sen 30, 195.8

fast on a cam shaft 29 journaled vertically in the attachment frame. In timed relation with the reciprocation of the needle bar, step-by-step rotary motion in the direction of the curved arrow in Fig. 3 is thus imparted to a pattern cam 30 which is keyed to turn with the cam shaft 29.

The pattern cam is formed with a clos ed sinuous cam groove 31 defined between an inner side wall 32 and an outer side wall 33, it being understood that the configuration of the cam groove determines the pattern of workjogging movements effected by the attachment. The cam groove, therefore, may be of any selected configuration to produce with the attachment any desired pattern of, zigzag stitches.

The cam groove is tracked bya follower roller 34, which is journaled on, a follower pin 35 fixed to one extremity of a work-joggingmenrber 3 6 which at its opposite extremity carriesfa work-engaging foot 37. The work-jogging member is formed with an elongated slot 38 which extends lengthwise betweenfthe follower pin 35 and the work-engaging foot37. The slot 38 accommodates a fulcrum'pin 39 which is carried by a slider 40 confined to move along die. attachment frame. The slider may be shifted alpng thefframe by means of a finger grip 41 to carrythe fulcrum pin to any selected position along the slot 358 i screw 4} .which passes through a'slot in the slider and is threaded into, the frame provides a mea ii s by which the slider may be clamped in any elated Pet i n f dihs heht- T at b l= eh i the rat hi the have: ahh h 6 t d, h h swimmer messiah? qt rh ls-iqeihs may? at h h w h h hark-chas n fhtr ta may djhs sdr rs ahjdai ag hr P h rt ahi y at an, e i h l 111 "4, "6f w ich; the erpgs t e r mity s a ac ty ,a tag nist ame', by a riyp P a whi h s, threaded. the hl s a sewed b s rews 47 4. 9 he' ra a" t 1 .rr ll, he-hhs srstshd t a t e s at has! Phi. shhhes h 31 benea h? a ta hmsht me. as he rex s-ih i me ihh 3 ve si as; crum e c l tes, Qf'the Workss. s .ahhht and t teeth? th Qt was hi he fsl hw h s. as; th a m o at he, h lhwer'a s hm tal, hr t e. a at hh 4 w an r (i ah r h s ts ar hfhP Y P a 4 h ahsh t ik 4,; th eats}. as Fates aflc m. more Q'QPF QIl h 'Q Y P the ambe h an n h Path o 1? h Phi hh. a thsratt tn. c n k ur e e t lql e an n aer 1 pwapa alo e thh Fi hr t th pa c th sl awer P n ra} hE 1 h, F F?d? L hil vit t- 9 9fl w h es ab she lsihsgat rihsis a hlarth at when at a y ins ant may be represented as occurring along aline tangentto he a e hah, th tahssh se a 2l.A'- Q The instantaneous path'of movementof any point on t e rahs as m s li sw sssa ahlaht hs. ll t as atat s nt s ah h s, n th hh hj h ii int s h h a thahte the shhts ett ahhh he i which a t as of he. ssh? sh 9 ?hh i 9 ba h, hf N wh sh h h t H s. ta g atsd I his; W9 S ns? ai hs; are V. VI 1 a s machine attachments of this type, the overall dimensions of the pattern cam are limited and as a result the characteristics of the inner and outer cam groove side walls differ markedly. Whereas the curves and slopes of the outer cam groove side wall 33 are comparatively smooth and gradual, those of the inner side wall 32 are abrupt and sharply angled. The actuating mechanism of the present invention is advantageous in that it limits the path of movement of the cam follower in such a manner that the outer cam groove side wall is called upon to impart a proportionately greater share of efiort in jogging 3 the cam follower thereby providing for easier and smoother actuation of the attachment and minimizing the possibility of binding or jamming of the parts.

To this end, the pivot pin 45 of the anchor link 44 is positioned with respect to the frame so as to define a cam follower pin path M, all parts of which, as illustrated in Fig. 3, are inclined with respect to the line X--X joining the axis of the cam follower pin 35 and the center of rotation of the pattern cam.

In the preferred embodiment of the drawings, the inclination of the cam follower pin path occurs outwardly from the center of pattern cam rotation and in the direction C of pattern cam rotation taken at the cam follower. Thus within its range of movement along the path M, the cam follower pin will at any instant have an instantaneous path of movement such as A or A depending, respectively, upon whether the pin is being moved outwardly by the inner cam groove side wall 32 or being moved in wardly by the outer cam groove side wall 33.

The path of outward cam follower movement A being inclined in the direction C of pattern cam movement encourages cam follower movement in this direction and reduces the effort required by the inner cam groove side wall 32 to move the follower outwardly. By the same token, the effort required by the outer cam groove side wall 33 to move the cam follower inwardly is correspondingly increased, however, the more gradual cam surfaces on the outer side wall are more suitable for delivering this increased increment of effort and, therefore, it is advantageous that the inner cam groove side wall be favored in the direction of lesser effort requirements.

Since all parts of the cam follower path are inclined with respect to the pattern cam radius which contains the cam-follower pin, the jogging motion of the work-engaging foot 37 will not be symmetrical about the center line of stitch formation, however, this offset effect will not be objectionable if the inclination of the cam follower path is kept within reasonable bounds. For instance, if the maximum error in symmetry of the jogging foot remains less than the diameter of the sewing thread, the assymmetrical movement of the foot will not be objectionable. As illustrated in Figs. 1 and 3, the anchor link 44 is preferably disposed substantially in continuation of the work-jogging member 36 so that the inclination of the cam follower path will be small. The anchor link pivot pin 45 is, however, offset from the line Y-Y, which passes through the fulcrum pin 39 and the cam follower pin 35 of the work-jogging member, and is disposed on the same side of the line Y--Y as is the center of pattern cam rotation. The work-jogging member 36 and the anchor link 44 thus provide a toggle joint, the follower pin 35 constituting a toggle knee. The toggle joint is arranged so as to be broken in one direction, that is, of direction A in Fig. 3 so as to favor movement of the cam follower pin in the direction A.

Having thus described the nature of the invention, what I claim herein is:

1. In a sewing machine work-jogging attachment, an attachment frame adapted to be secured to saidsewing machine, a work-jogging member slidingly pivoted to said frame, a work-engaging foot carried by said member, an anchor link, a pivotal connection securing one extremity of said anchor link to said frame, a pivot pin connecting said anchor link to said work-jogging member, said membet and said anchor link together providing a toggle joint, said pivot pin therebetween defining a toggle knee, a cam follower carried by said pivot pin, and cam means carried by said frame and adapted to be actuated by said sewing machine for jogging said toggle knee.

2. In a work-jogging attachment for a sewing machine, an attachment frame, a work-jogging member slidingly pivoted to said frame, a work-engaging foot carried by said work-jogging member, a cam follower carried by said work jogging member, a cam member journaled for rotation on said frame, said cam member being formed with a closed cam groove defined between inner and outer side walls arranged to embrace the cam follower therebetween, and means limiting the path of movement of said cam follower so as to favor cooperation of said follower with the same one of said cam groove side walls.

3. in a work-jogging attachment for a sewing machine, an attachment frame, a pattern cam journaled for rotation on said frame, said pattern cam being formed with a cam groove having a closed path, means for imparting rotary motion in one direction to said pattern cam, a work jogging member slidingly pivoted to said frame, a work engaging foot carried by said work-jogging member, a cam follower carried by said work-jogging member and disposed to track said cam groove, and a cam follower controlling means carried by said frame for constraining movement of said cam follower in a path inclined with respect to a line joining the center of the cam follower with the center of rotation of said pattern cam.

4. A device as set forth in claim 3 in which said cam follower controlling means includes an anchor link pivotally connected to said frame and to said work jogging member.

5. A device as set forth in claim 3 in which said cam follower controlling means includes an anchor link pivotally connected to said work-jogging member, and means pivotally securing said anchor link to said frame at one side of a line extending through said cam follower and through said slidingly pivoted connection with said attachment frame.

6. In a sewing machine work-jogging attachment, :1 frame adapted to be secured to a sewing machine, a pattern-cam having a closed cam groove journaled on said frame, means actuated by said sewing machine for imparting stepby-step rotary motion to said pattern earn, a work-jogging member, a work-engaging foot carried by said member, a follower on said member disposed to track said pattern cam groove, said work-jogging member being formed with an elongated slot extending lengthwise between said pattern cam follower and said work-engaging foot, 21 fulcrum pin carried by said frame and disposed to enter said slot, an anchor link pivoted on said pattern cam follower and disposed to extend away from said workengaging foot, and a pin pivotally securing said anchor link to said frame at one side of a line extending through said cam follower and through the fulcrum pin for said work-jogging member.

References Cited in the file of this patent UNITED STATES PATENTS 

